1.0 INTRODUCTION

The site investigation is the one thing that must be done before starting the construction of the building. This is because the soil condition at the site need to be identifies to determine the suitable foundation use for the building. As we know, soil play a main role to support the load that come from the building and the building need a suitable foundation to transfer the load to the ground. Therefore, the investigation of soil need to be done to identify the type of soil to ensure the soil can carry the load.
In investigating the soil condition, the probe mackintosh commonly use in this country , Malaysia. Probe mackintosh may consist of two type which it is normal probe mackintosh and JKR probe mackintosh. The difference of these equipment is the degree of its degree of it penetration cone. Although they differ in the slope of Cone penetration but its function remains the same. The purpose of the investigation by using probe mackintosh is to take the soil in the ground as a sample to identify the condition of soil and to identify the strength of soil to carry load from the building.
In the process of investigating soil by using probe mackintosh, our group has chosen Lala land which is located in the Universiti Teknologi Mara (UITM), Seri Iskandar,Perak to practice soil investigation work by using mackintosh probe. The selection of location is to facilitate the work done. Besides that, we have also given the task to prepare a report relating to the assignment received which we have to identify the condition of the soil at this location and should be recorded for the purpose of determining the strength of the soil.

2.0 OBJECTIVE

The main objective of probe mackintosh works is to: * Collecting a disturbed soil sample for grain-size analysis and soil classification * Determine sub-surface stratigraphy and identity materials present * Evaluate soil density and in-situ stress conditions * Estimate geotechnical parameters

3.0 SCOPE OF STUDY

The soil investigation work done, we were given the task to investigate and practice of soil investigation works to get information about ground conditions we have chosen. as mentioned earlier, the location of our study conducted in Lala land located in the Universiti Teeknologi Mara (UITM), Seri Iskandar,Perak.
In completing this task, we have explained the equipment used and procedures to use the equipment. Besides that, we also explained the steps to doing this investigation by the lecturers and we are required to provide reports on condition land which has been studied.
The information obtained will be recorded and the results will be inserted into the report. The purpose of recording is to identify the soil area that we examine. Besides that, the information obtained can also determine the basic suitability of soil conditions according to the records was obtained.

4.0 EQUIPMENTS

In the mackintosh probe work, equipment used should be in good condition to ensure that the work will be done effectively and easily. Selection of equipment which is not good or bad can affect the process of investigations. For example, the steel rod shall be in a straight line so that it can be easily removed after completion of the work done while the selection of a bent steel rod will result in cone penetrometer difficult to remove and it can affect the soil samples were obtained.
The equipment that will be used in probe mackintosh is explained below:

1) Cone penetrometer
The cone penetrometers are used to collect the soil sample in the ground to identify the soil condition. It will be jointed with steel rod to allow the cone penetrometer penetrate into the soil. When the steel rods are hitting by the mankley hammer, the cone penetrometer will be pushed into the ground. The soil sample will e stick to the cone penetrometer during the investigating works finished.

Photo 4.1 cone penetrator

2) Coupling Coupling are use to joint the steel rod. This is because the steel rods are not long enough to push the cone penetrometer into the soil. This is because the length of each steel rod is one meter only and its need to penetrate 15 meter into the ground or 400 (maximum) hitting of mankley hammer.

Photo 4.2 coupling

3) Mankley hammer Mankley hammer are use to hit the rod to ensure the cone penetrometer penetrate into the ground. There are stopper in the mankley hammer where it was used to stop the mankley hammer from lifting to the ground. The weight of makley hammer is 5 kilogram. With that weight are enough to push the cone penetrometer penetrate into the ground.

Photo 4.3 Mankley hammer

4) Puller Puller is used to pull out the cone penetrometer from the ground. the puller will be attached to steel rod before pull out the cone penetrometer. Before the puller attached to the steel rod, the mankley hammer and stopper need to remove. To use the puller, two person are need to pull the puller to remove the steel rod and cone penetrometer out form the ground.

Photo 4.4 puller

5) Steel rod
Steel rod are jointed between the cone penetrometer and mankley hammer. The steel rod are used to push the cone penetrometer into the ground. On the surface steel rod will be mark with liquid paper for every one feet to measure the number of hitting for every one feet depth. Each steel rod length is one meter. For the next steel rod will be joint with the first steel rod by using coupling.

Photo 4.5 steel rod

6) Pipe wrench
Pipe wrench are used to tighten the jointing of the equipment such as connection between steel rods and coupling. Beside that, pipe wrench also used to loose the connection of equipment. In the probe mackintosh works, two pipe wrenches are need to tighten or loosed the connection of equipment to ease the works that will be done.

Photo 4.6 pipe wrench

7) Measuring tape
Measuring tape are used to measure the distance between the point. The distance between each point is 10 meter, so the measuring tape need to enough long to ease the works done. Furthermore, the measuring tape is also used to measure during marking on the steel rod for each one feet.

Photo 4.7 measuring tape

8) Stopper

Stopper is a tool that works to stop mankley hammer from sliding down. It is found within mankley hammer where it will first be installed before mankley hammer. It will be connected at the end of the steel rod and hammer will be installed after mankley hammer.

Photo 4.8 stopper

5.0 METHODS OF INVESTIGATION

The initiation of investigation, the location need to identify before starting the investigation works. At the early stage of investigation, the point that involved in investigation need to be mark. In determining the method of investigation, there are two methods commonly used to do the works mackintosh probe, there are straight line methods and triangle method. in the study of soil conditions by using probe mackintosh, we have applied the straight line method.
The first step to do this investigation that need to do is removed the top soil. Removing top soil is to ensure the others material such as grass, root and others from interfere the soil sample. The top soil can be removed by using the hoe (photo 5.1)

(Photo 5.1) Removing top soil work

According to the procedure, the equipment also needs to assemble before the works start. After that, the stopper need to jointed with the steel rod before the mankley hammer install. Before install the steel rod, stopper, and mankley hammer, the grease or oil need to sweep up for an easy dissembles later (Photo 5.2). Make sure the steel rod already mark by liquid paper for every 0.3 meter or one feet.

(Photo 5.2) sweep the oil to the equipment

After finish jointing the equipment, all the works can be done and make sure all equipment is set up on the ground. In the beginning, the steel rod need to hold by two person to ensure the steel rod or cone penetration can penetrate in straight into the ground. After that, the mankley hammer will be pulled until it reach the maximum and then drop it freely. When the rod is hit into the ground, the total number of hitting will be calculated until it reaches one foot. Hitting the next calculation will be made on each of the next feet up to one meter. The information will be recorded into a piece of paper. The soil will be penetrated until it reach 15 meter or he blow is more than 400 for 0.3 m penetration. In this investigation, we are need to do only 3 meter. It is mean we only need to use three steel rod only and calculate the result. To continue the investigation, the coupling are need to joint between the two steel rods. The jointing will be continue until it reach 3 meter .After finish the investigation, the steel rods and cone penetration need to pull out by using puller. To pull out the steel rod and cone penetration, two persons is need to pull it out. The same methods will be done to another point. The soil sample will be collect and will be put in a oven for a several hour to record the moisture content in the soil that has been investigated. The soil should be weighed to obtain dry weight before and after drying before put in the oven.
To identify the water content in the soil, the formula below will be used:
Formula:
(Wet soil – Dry soil / Dry soil) x 100

6.0 DATA COLLECTED

Figure 6.1 below showed data that have been collected according to the numbers of blows for every point according to the depth. Each point is recorded as below. While figure 6.2 show the graph that refer to the figure 6.1.

DEPTH (m) | POINT A | POIINT B | POINT C | 0.3 | 150 | 32 | 36 | 0.6 | 42 | 42 | 35 | 0.9 | 61 | 13 | 81 | 1.2 | 35 | 6 | 84 | 1.5 | 49 | 9 | 103 | 1.8 | 46 | 7 | 73 | 2.1 | 64 | 10 | 71 | 2.4 | 65 | 8 | 83 | 2.7 | 60 | 7 | 96 | 3.0 | 125 | 7 | 74 |

(Figure 6.1) Data recorded

(Figure 6.2) The following graph show the result collected

According to the formula below, the soil sample needs to examine the water content in the soil. After that the calculation will be done to determine the moisture content in the soil. The existence of moisture content will be determined after the weight of wet soil minus dry soil. The wet soil is the soil that collected before put in the oven while the dry soil is the soil that has been put in the oven. Below are some calculations about the percentage of moisture content that exist in the soil in each point:
Formula:
[ (Wet soil – Dry soil / Dry soil) x 100 ]

Point A
Dry soil = 20, Wet soil = 21
Calculation:
21 – 20 / 20g x 100 = 5 %
Total percentage = 5%

Point B
Dry soil = 28 , Wet soil = 30
Calculation:
30 – 28 / 28 x 100 = 7 %
Total percentage = 7 %

Point C
Dry soil = 32, Wet soil = 33
Calculation:
33 – 32 / 32 x 100 = 3 %
Total percentage = 3 %

7.0 CONCLUSION

As a conclusion, probe mackintosh is very useful in the site investigation to measure the suitability of soil for the construction works. Although it is not properly work but its still can be used to investigate the soil condition. The advantages of using this method is may reduce in cost and easy to do. As we know, this method are still used in this country to investigating soil condition. As a student, practicing this methods also easy to understand because it is very simple compared to other methods. Beside that, with practicing this method of soil investigation give more knowledge about how the soil investigation done and how to measure the existing the moisture content in the soil. After that, with that information the suitable foundation also can be determined.

8.0) REFERENCES

Internet: 1) http://www.foundtest.com.my/services/mpt.html 2) http://www.scribd.com/doc/43714071/Probe-Mackintosh-Test 3) http://theconstructor.org/geotechnical/mackintosh-probe-test/3801/